Minimum phase model of a dynamic spectral analysis of sounds at the periphery of hearing

The model consists of independent frequency-channels the amplitude-frequency characteristics (AFC) of which are assigned by the investigator. The phase characteristics are computed. Concrete minimum-phase model is described and illustrated. The temporal and frequency characteristics of this model are consistent with experimental data on peripheral auditory system. The AFC can be easily reformed, so the model is convenient for investigation of functional models of peripheral auditory analysis.     

Coagglutination test: a simple and rapid immunodiagnostic test for parvovirus infection in dogs

Pheochromocytoma is rarely observed during pregnancy and not easily diagnosed, especially since the clinical manifestations may mimic common gravid hypertension. The maternal and fetal prognosis depends on early diagnosis and multidisciplinary management preparing for tumor resection. Appropriate laboratory tests easily provide the positive diagnosis, if they are ordered. The tumor is localized by ultrasonography or magnetic resonance imaging (MRI). By prescribing an alpha-blocker, it is possible to prepare the resection as a function of term, before or after delivery. This strategy allows a reduction in maternal and fetal mortality which is high if the pheochromocytoma goes undiagnosed.     

Validity of epidemiological classification: study of asymptomatic properties of a discriminant criterion

Aiming to assess the presence of selected anaerobic microorganisms in root canals of human teeth with chronic apical periodontitis. 25 central and lateral upper incisors presenting with radiographic evidence of chronic apical periodontitis were studied. The pulp chamber was opened under aseptic conditions and samples of the root canal content were collected with sterile absorbent paper points, which were placed and dispersed in test tubes containing reduced transport medium RTT. Aliquots were dried on glass slides and stained by indirect immunofluorescence for detection of Actinomyces viscosus, Fusobacterium nucleatum, Porphyromonas gingivalis and Prevotella intermedia. The results showed a positive indirect immunofluorescence reaction in 24 of the 25 samples. Fourteen were positive for the specie Actinomyces viscosus, 12 for Prevotella intermedia, 10 for Fusobacterium nucleatum and 4 for Porphyromonas gingivalis. A semiquantitative assay was easily implemented for assessment of degree of infection by the organisms in individual cases.     

Thermodynamic Efficiency of Using a Separating Agent in Distillation Processes

Theoretical Foundations of Chemical Engineering - The limit of the productivity of a binary distillation column is obtained depending on heat consumption. It is shown that the consumption of heat...     

Experience in the health promotion of children in opisthorchiasis foci

The analysis covers 2555 appendectomies, performed on an emergency and scheduled surgery basis in the clinic of emergency surgery.--State University Hospital "Queen Giovanna", Sofia, over the period 1985-1997. Relaparotomy is necessitated in 28 cases (1.09 per cent) because of various postoperative complications. Data are presented on the number of relaparotomies, done under conditions of emergency and scheduled surgery, and with a special reference to the pathoanatomical character of appendicitis. The underlying causes of undertaking relaparotomy and postoperative lethality are analyzed. As shown by the obtained results post-relaparotomy mortality rate is the highest after primary operation for destructive form of appendicitis and advanced form of peritonitis.     

The value of the Health Assessment Questionnaire and special patient-generated scales to demonstrate change in systemic sclerosis patients over time

OBJECTIVE: To determine the validity and usefulness of a modified Health Assessment Questionnaire (HAQ) for measurement of disease status and changes in disease status over time in patients with systemic sclerosis (SSc). METHODS: Since 1985, 1,250 patients attending the University of Pittsburgh Scleroderma Clinic have completed a modified HAQ annually. In addition to the standard HAQ questions about disability, the questionnaire includes visual analog scales (VAS) to evaluate SSc organ system symptoms, Raynaud's phenomenon, gastrointestinal (GI) tract and lung involvement, pain, and overall disease severity. In this study, the disability index (DI) (from the HAQ) and the VAS scores (on a 0-3 scale) were compared with various clinical and laboratory features recorded within 3 months of administration of the HAQ and VAS, using t-tests and Spearman's correlation tests. RESULTS: The HAQ DI correlated directly with skin involvement, scleroderma heart or kidney disease, tendon friction rubs, hand contractures, and proximal muscle strength. Over time, the DI correlated with changes in skin score and was a good predictor of survival. There was a significant improvement in the DI during a 2-year time period in patients treated with D-penicillamine. The VAS for digital ulcers, GI symptoms, and lung symptoms correlated very closely with subjective and objective findings for these organ systems. The presence of new digital ulcers or improvement in digital ulcers showed significant associations with the Vascular scale, new GI symptoms or improvement in GI symptoms and institution of H2-blockers showed appropriate strong correlations with the GI scale, and changes in the forced vital capacity had an excellent correlation with the Lung scale (r = 0.58, P < 0.001). By Cox regression analysis, the HAQ DI was one of the best predictors of survival. CONCLUSION: These data provide convincing evidence that a self-administered questionnaire is an accurate and inexpensive tool to measure disease status changes in SSc. Prospective studies with the HAQ administered at regular intervals, as in controlled trials, should be performed to further assess the benefits and limitations of this instrument.     

Thermal-hydraulic tests of a recirculation cooling installation for the Rostov nuclear power station

Results obtained from thermal-hydraulic tests of the recirculation cooling installation used as part of the air cooling system under the containments of the Rostov nuclear power station Units 3 and 4 are presented. The operating modes of the installation during normal operation (air cooling on the surface of finned tubes), under the conditions of anticipated operational occurrences (air cooling and steam condensation from a steam-air mixture), and during an accident (condensation of pure steam) are considered. Agreement is obtained between the results of tests and calculations carried out according to the recommendations given in the relevant regulatory documents. A procedure of carrying out thermal calculation for the case of steam condensation from a steam-air mixture on the surface of fins is proposed. The possibility of efficient use of the recirculation cooling installation in the system for reducing emergency pressure under the containment of a nuclear power station is demonstrated.     

Biodemographic trajectories of longevity

Old-age survival has increased substantially since 1950. Death rates decelerate with age for insects, worms, and yeast, as well as humans. This evidence of extended postreproductive survival is puzzling. Three biodemographic insights--concerning the correlation of death rates across age, individual differences in survival chances, and induced alterations in age patterns of fertility and mortality--offer clues and suggest research on the failure of complicated systems, on new demographic equations for evolutionary theory, and on fertility-longevity interactions. Nongenetic changes account for increases in human life-spans to date. Explication of these causes and the genetic license for extended survival, as well as discovery of genes and other survival attributes affecting longevity, will lead to even longer lives.     

Positive selection is a general phenomenon in the evolution of abalone sperm lysin

Lysin is a 16kDa acrosomal protein used by abalone sperm to create a hole in the egg vitelline envelope (VE). The interaction of lysin with the VE is species-selective and is one step in the multistep fertilization process that restricts heterospecific (cross-species) fertilization. For this reason, the evolution of lysin could play a role in establishing prezygotic reproductive isolation between species. Previously, we sequenced sperm lysin cDNAs from seven California abalone species and showed that positive Darwinian selection promotes their divergence. In this paper an additional 13 lysin sequences are presented representing species from Japan, Taiwan, Australia, New Zealand, South Africa, and Europe. The total of 20 sequences represents the most extensive analysis of a fertilization protein to date. The phylogenetic analysis divides the sequences into two major clades, one composed of species from the northern Pacific (California and Japan) and the other composed of species from other parts of the world. Analysis of nucleotide substitution demonstrates that positive selection is a general process in the evolution of this fertilization protein. Analysis of nucleotide and codon usage bias shows that neither parameter can account for the robust data supporting positive selection. The selection pressure responsible for the positive selection on lysin remains unknown.